mirror of
https://github.com/mihakralj/QuanTAlib.git
synced 2026-07-27 17:27:43 +00:00
Miha Kralj
69 lines
2.5 KiB
Plaintext
69 lines
2.5 KiB
Plaintext
// Licensed under the Apache License, Version 2.0
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// © mihakralj
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//@version=6
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indicator("Directional Movement Index (DX)", "DX", overlay=false)
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//@function Calculates DX using Wilder's smoothing with compensated RMA
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//@param period Number of bars used in the calculation
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//@returns tuple of DX value, +DI, -DI
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//@optimized Uses Wilder's smoothing (RMA) with warmup compensation for accurate values from bar 1
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dx(simple int period) =>
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if period <= 0
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runtime.error("Period must be greater than 0")
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float alpha = 1.0 / period
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float beta = 1.0 - alpha
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float tr = 0.0
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float plus_dm = 0.0
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float minus_dm = 0.0
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if na(close[1])
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tr := high - low
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else
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tr := math.max(high - low, math.max(math.abs(high - close[1]), math.abs(low - close[1])))
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float upMove = high - high[1]
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float downMove = low[1] - low
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if upMove > downMove and upMove > 0
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plus_dm := upMove
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if downMove > upMove and downMove > 0
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minus_dm := downMove
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var bool warmup = true
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var float e = 1.0
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var float tr_ema = 0.0
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var float tr_result = tr
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var float plus_dm_ema = 0.0
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var float plus_dm_result = plus_dm
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var float minus_dm_ema = 0.0
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var float minus_dm_result = minus_dm
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tr_ema := alpha * (tr - tr_ema) + tr_ema
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plus_dm_ema := alpha * (plus_dm - plus_dm_ema) + plus_dm_ema
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minus_dm_ema := alpha * (minus_dm - minus_dm_ema) + minus_dm_ema
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if warmup
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e *= beta
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float c = 1.0 / (1.0 - e)
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tr_result := c * tr_ema
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plus_dm_result := c * plus_dm_ema
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minus_dm_result := c * minus_dm_ema
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warmup := e > 1e-10
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else
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tr_result := tr_ema
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plus_dm_result := plus_dm_ema
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minus_dm_result := minus_dm_ema
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float plus_di = tr_result != 0.0 ? 100.0 * plus_dm_result / tr_result : 0.0
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float minus_di = tr_result != 0.0 ? 100.0 * minus_dm_result / tr_result : 0.0
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float di_sum = plus_di + minus_di
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float dx_value = di_sum != 0.0 ? 100.0 * math.abs(plus_di - minus_di) / di_sum : 0.0
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[dx_value, plus_di, minus_di]
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// ---------- Main loop ----------
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// Inputs
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i_period = input.int(14, "Period", minval=1, tooltip="Number of bars used in the calculation")
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// Calculation
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[dx_value, plus_di, minus_di] = dx(i_period)
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// Plot
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plot(dx_value, "DX", color=color.yellow, linewidth=2)
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plot(plus_di, "+DI", color=color.green, linewidth=1)
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plot(minus_di, "-DI", color=color.red, linewidth=1)
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hline(25, "Strong Trend Threshold", color=color.gray, linestyle=hline.style_dashed)
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